Methods of producing monocyclic aromatic hydrocarbons such as BTX (benzene, toluene and xylene) from an oil feedstock such as a cracked light oil (hereinafter light cycle oil and also abbreviated as “LCO”) containing a large amount of polycyclic aromatics obtained from a fluid catalytic cracking (hereinafter also abbreviated as “FCC”) unit, or a light naphtha or heavy naphtha or the like obtained from a crude oil distillation unit, using a catalytic aromatic production reaction that employs an aromatic production catalyst are already well known.
The production systems of aromatic hydrocarbons using aromatic production catalyst generally employ a fixed bed system, a moving bed system or a fluidized-bed system. In Patent Document 1, a producing method of monocyclic aromatic hydrocarbons employing fluidized-bed system is disclosed. In a fluidized-bed reaction apparatus employing fluidized-bed system, the aromatic production catalyst and the feedstock can maintain in a state of similar to a complete mixing, and the reaction temperature becomes easy to maintain uniformity. In addition, the aromatic production catalyst, which is deteriorated by coke in a case where the feedstock becomes heavier, is withdrawn appropriately from the fluidized-bed reaction reactor, an adhered coke is burned, and heating the aromatic production catalyst can therefore be performed smoothly.